THE NERVOUS SYSTEM AND CONSCIOUSNESS. 741 



was left, and actually succeeded in removing the acid. Pfltiger was 

 so astonished and impressed by his exjjeriment that he declared the 

 spinal cord to be possessed of sensory powers — that is, caj^able of con- 

 sciousness, I have stated this experiment in detail because it is the 

 most striking among the many facts which have led to such a conclu- 

 sion as that of Dr. Hammond in his address at Lehigh University, in 

 October of last year. The address may be found in the November 

 number of " The Popular Science Monthly." Dr. Hammond writes, 

 "Suffice it to say that these experiments all go to establish the fact 

 that the spinal cord, after the complete removal of the brain, has the 



Fig. 9.— Inferior Surface of the Cerebellttm. (Sappey, after Hirschfeld.) 1, 1, inferior ver- 

 miform process ; 2, 2, median fissure of the cerebellum ; 3, 3, 3, lobea and lobules of the cere- 

 bellar hemispheres; 4, "amygdala," or almond-like lobe; 5, lobule of the pneumou:astric ; 6, 

 pons Varolii ; 7, median groove on the same; 8, middle peduncle of the cerebellum; 9, cut 

 surface of medulla; 10, anterior extremity of the great circumferential fissure; 11, anterior 

 border of the upper surface of the cerebellum; 1'2, motor root of the trigeminal nerve; 13, 

 sensory root of the same ; 14, nerve of the external ocular muscle ; 15, facial nerve ; 16, nerve of 

 Wrisberg ; 17, auditory nerve ; 18, glosso-pharyngeal nerve ; 19, pneumogastrin nerve ; 20, spinal 

 accessory nerve; 21, hypoglossal nerve. 



power of perception and volition, and that the actions performed are 

 to all intents and purposes as perfect of their kind as they would be 

 were the brain in its place." Though Dr. Hammond does not mention 

 Pfliiger's experiment, he cites other instances to the same effect. He 

 has seen " the headless body of the rattlesnake coil itself into a threat- 

 ening attitude, and, when irritated, strike its bleeding trunk against 

 the offending body." Perrault reports that " a viper whose head had 

 been cut off moved determinedly toward its hole in the wall." Neither 

 these instances, nor the others which Dr. Hammond names in this con- 

 nection, are as striking as Pfliiger's experiment. The noticeable feat- 

 ure in this experiment is the fact that the muscular movements which 

 appear upon irritation of the afferent fibers seem not merely to display 

 a general conformity to ends, but to adjust themselves to changed con- 

 ditions. Lotze, remembering the involuntary course of acquired move- 

 ments in man, says, "These actions which point to a consciousness 

 may be simply the back-workings of consciousness upon the mechan- 

 ism of the reflex organ." Wundt thinks that, "if with Darwin we 



